What's the difference? (Control tubes)

[BDPetersen]

The elevator and rudder push-pull tubes in the tail cone, the 6'+ long ones. My '66 C has aluminum tubes, 1 1/2" (or greater) in diameter, marked part # 710022. A bit of surface corrosion, I inquired of LASAR about replacements. They said the superseded # was 915038 and quoted a price. I then searched that number to find at least 1 offering for that # that was apparently a smaller diameter steel tube. A call back to LASAR to ask which was newer (or preferable), he opined that the aluminum ones were. Now I'm not sure. Any ideas?

Corrosion X and scotch brite made mine look acceptable and a look inside of the tubes showed they were pristine internally. (Swabbed Corrosion X inside as well.)

[carl]

They are thin wall tube , surface corrosion is not a problem unless there is pitting. Mine were pitted and I am replacing them. The same tube diameter can use your existing tubing ends. If you change the tubing diameter size then you need to buy new tubing ends.

[Guest]

9 hours ago, carl said:

They are thin wall tube , surface corrosion is not a problem unless there is pitting. Mine were pitted and I am replacing them. The same tube diameter can use your existing tubing ends. If you change the tubing diameter size then you need to buy new tubing ends.

Carl,

How do you know what alloy of aluminum the tube is made from?  It could be fatal if you get it wrong.

Clarence

[BDPetersen]

It seems the steel tube version is the later version, contrary to my friend at LASAR opinion. I'm sure I can find some pitting on mine, but the IA doesn't seem concerned at this point. I may consider the swap to steel if it is a step forward.

[BDPetersen]

Carl, when you replaced yours were the aluminum tubes still available?

[carl]

i meant . i have ordered the exact replacement tube from the mooney factory . 

if you get replacement tubes from the factory that are not the exact diameter then you must also get the matching end pieces to fit those tubes. 

but i mean replace existing diameter with same thing . i would not change sizes . 

i am told the end pieces are more then the tubes 

i think important structures should be original factory purchased if possible. 

 

the correct material or alloy would be hard to locate except through the factory . 

 

i ordered mine around christmas . i am waiting for them to arrive.

 

for clarity my ap ia ordered them working with chautauqua aircraft in ny state. 

 

i was told the factory had 6 tubes on hand for the m20e

@about $150 each . 

shipping is about that too. 

[BDPetersen]

Thanks. LASAR quoted a price of $363/ea for factory tubes. Noticed a pair of steel ones on eBay for $100, ends included. 

[StinkBug]

20 hours ago, carl said:

 

the correct material or alloy would be hard to locate except through the factory . 

 

The hard part is simply finding out what alloy the material is. Getting it is easy. I highly doubt they are using some super secret proprietary alloy for a tube, and there are tons of metal suppliers that can get you whatever you want. 

[Sabremech]

A sample of the original tubing can be sent to a lab for analysis. I've done this a number of times to determine the alloy for my own PMA parts.

David

[N601RX]

We have a scanning electron microscope in our foundry at work that will determine the elemental composition.  Once this is done then it's just a matter of comparing the element percentages to the composition of common alloys.   This will give you the alloy.  Then a hardness test or tension coupon pull test will deterime the heat treat condition.  The aluminum ones are likely 2024-t3. 

[cliffy]

According to Mooney Engineering the elevator tube and the two hinge bolts are the primary tail connection structural  points. 

Messing with the tube and you're messing with the primary connection of your tail.

Maybe correct factory parts are the way to go here? 

Just sayin

[BDPetersen]

I guess my curiosity was to see if anyone knew if the tubes evolved from aluminum to steel or vice versa and why. Maybe a better question would be is there a way to contact Mooney for guidance. I haven't run across a factory support number yet, but I probably am not searching correctly.

[Guest]

For a couple of hundred dollars why bother taking the chance?  What happens to future liability for this owner produced part should it fail?  Does the owner carry the same 18 liability limit as the manufacturer?

Clarence

[BDPetersen]

To be clear, at no time did I propose or consider an owner produced part. Not sure what prompted that aspect of this discussion. My only curiosity was in the difference in the two iterations of factory produced parts, aluminum then steel.

[kortopates]

I guess my curiosity was to see if anyone knew if the tubes evolved from aluminum to steel or vice versa and why. Maybe a better question would be is there a way to contact Mooney for guidance. I haven't run across a factory support number yet, but I probably am not searching correctly.

They don't take tech support calls but they do answer emails. See their website and send them an email. Stacey will get back to you.

Sent from my iPhone using Tapatalk

[Guest]

32 minutes ago, BDPetersen said:

To be clear, at no time did I propose or consider an owner produced part. Not sure what prompted that aspect of this discussion. My only curiosity was in the difference in the two iterations of factory produced parts, aluminum then steel.

Nor did I suggest that you were.. There are a few other posts describing methods to determine alloy and heat treatment.   We don't have an "Owner produced" option in Canada, so hence my question about liability.

Clarence

[BDPetersen]

But I think a nice piece of electrical conduit may just do the trick.

(OK, that was a joke.)

[Sabremech]

1 hour ago, M20Doc said:

Nor did I suggest that you were.. There are a few other posts describing methods to determine alloy and heat treatment.   We don't have an "Owner produced" option in Canada, so hence my question about liability.

Clarence

This is a part that I probably wouldn't do as an owner produced part unless there were no spares or replacements available. I would however consider FAA/PMA'ing these parts if Mooney quit producing them and there was a good demand for them to be worthwhile producing them.

David

[N601RX]

Owner produced parts still require the use approved data to manufacturer the part for anything that is structural.  This usually involves either getting factory drawings if available or working with a DER or FSDO reverse engineer and get the data approved.  Once this has been done the tube from Mooney will likely be cheaper of the two, but if all this is done correctly there should not be any difference between the tube purchased from Mooney and a tube purchased from a aircraft aluminum supplier that will also provide a copy of the material cert.

[carl]

This is from a rv -8 ,Michael Foss' , his blog RV-8 hanger .

 

I'm just causing trouble now with this statement " it's the same thing "

HAha

carl

[Guest]

8 hours ago, carl said:

This is from a rv -8 ,Michael Foss' , his blog RV-8 hanger .

 

I'm just causing trouble now with this statement " it's the same thing "

HAha

carl

The same in concept only.  Vans used "pop" style rivets to hold the end fitting in, while certified manufacturers use certified hardware, Cherry max rivets or Clovis pins etc.

Clarence

[mike28w]

Love the photo !!    I've eaten at many fast food places that weren't nearly as clean as the inside of that RV !!   WOW !

Edited January 27, 2016 by mike28w

[MB65E]

Really pretty install. Talented guy!

-Matt